The college football season is barely half finished, but Coca-Cola’s Sharon Byers already knows what her lasting memory will be.

Just a few weeks ago, an Ole Miss fan posted a photo of himself and an autographed football from Rebels coach Hugh Freeze on Twitter. In the message, he thanked Coca-Cola for sending him the football unexpectedly.

Coke Zero uses social media hookups to surprise college football fans with gifts.

That kind of social media outreach has been central to Coke Zero’s marketing this fall during college football.

Coke’s digital agency in Atlanta, CSE, has a team of more than a dozen people from its corporate office who constantly monitor Facebook and Twitter. When they find someone commenting on college football with a substantial list of followers (roughly 500 or more), Coke will “surprise and delight,” as Byers put it, by sending them an unexpected gift like a signed football, helmet or game tickets — items the company has access to through its hundreds of college relationships as a sponsor or official product in stadiums.

These social media hookups have provided an outlet for Coke Zero to connect with fans, who then become unofficial ambassadors for the brand through their online posts.

When they post photos and messages on Facebook and Twitter about a surprise gift from Coke, “we know we’re hitting our target and these people essentially are selling the brand for us,” said Byers, senior vice president of sports and entertainment marketing for Coca-Cola.

Byers describes the target as college students specifically, and more broadly the 18-34 demographic that closely follows college football. Coke Zero is the brand that the company has aligned with football for the last four years, she said, and they continue to evolve the brand’s college football strategy, but Byers believes this kind of outreach establishes “advocates for life.”

Earlier this season, a Vanderbilt student tweeted that he and three friends were traveling to Chicago for the Northwestern game and mentioned that they didn’t have tickets. CSE execs found the message and arranged for them to receive four tickets to the game for free. Byers estimates that Coca-Cola will give away thousands of tickets and memorabilia through the social channels and MyCokeRewards.com.

Coke’s social media outreach has come in other forms as well. On several campuses during game days, Coke has arranged what it calls “meet-ups” near the stadium. Through its social channels, Coke invites college students to a site where more of these gifts are awarded to those who show up the earliest. Some of these “meet-ups” have drawn as many as 100 students and Coca-Cola intends to do a handful each weekend throughout the season, many of which will be held at high-profile SEC games.

Marketing through social media “is an ever-evolving process,” Byers said. “As always it depends on your brand. But for Coke Zero, connecting sports and the idea of surprising people on campus is creating cheerleaders for our brand. We see it really working. … When we see a consumer base responding like this, we do feel like this is something that we can use in a much broader sense in 2013 and 2014.”